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KVM/arm64 fixes for 5.11, take #2 

- Don't allow tagged pointers to point to memslots
 - Filter out ARMv8.1+ PMU events on v8.0 hardware
 - Hide PMU registers from userspace when no PMU is configured
 - More PMU cleanups
 - Don't try to handle broken PSCI firmware
 - More sys_reg() to reg_to_encoding() conversions
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Merge tag 'kvmarm-fixes-5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 5.11, take #2

- Don't allow tagged pointers to point to memslots
- Filter out ARMv8.1+ PMU events on v8.0 hardware
- Hide PMU registers from userspace when no PMU is configured
- More PMU cleanups
- Don't try to handle broken PSCI firmware
- More sys_reg() to reg_to_encoding() conversions
master
Paolo Bonzini 2021-01-25 18:52:01 -05:00
parent 7c53f6b671 139bc8a614
commit 615099b01e
6 changed files with 74 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
Documentation/virt/kvm/api.rst
View File

@ -1281,6 +1281,9 @@ field userspace_addr, which must point at user addressable memory for
the entire memory slot size. Any object may back this memory, including
anonymous memory, ordinary files, and hugetlbfs.
On architectures that support a form of address tagging, userspace_addr must
be an untagged address.
It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr
be identical. This allows large pages in the guest to be backed by large
pages in the host.

3
arch/arm64/kvm/arm.c
View File

@ -1396,8 +1396,9 @@ static void cpu_init_hyp_mode(void)
* Calculate the raw per-cpu offset without a translation from the
* kernel's mapping to the linear mapping, and store it in tpidr_el2
* so that we can use adr_l to access per-cpu variables in EL2.
* Also drop the KASAN tag which gets in the way...
*/
params->tpidr_el2 = (unsigned long)this_cpu_ptr_nvhe_sym(__per_cpu_start) -
params->tpidr_el2 = (unsigned long)kasan_reset_tag(this_cpu_ptr_nvhe_sym(__per_cpu_start)) -
(unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start));
params->mair_el2 = read_sysreg(mair_el1);

13
arch/arm64/kvm/hyp/nvhe/psci-relay.c
View File

@ -77,12 +77,6 @@ static unsigned long psci_forward(struct kvm_cpu_context *host_ctxt)
cpu_reg(host_ctxt, 2), cpu_reg(host_ctxt, 3));
}
static __noreturn unsigned long psci_forward_noreturn(struct kvm_cpu_context *host_ctxt)
{
psci_forward(host_ctxt);
hyp_panic(); /* unreachable */
}
static unsigned int find_cpu_id(u64 mpidr)
{
unsigned int i;
@ -251,10 +245,13 @@ static unsigned long psci_0_2_handler(u64 func_id, struct kvm_cpu_context *host_
case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
return psci_forward(host_ctxt);
/*
* SYSTEM_OFF/RESET should not return according to the spec.
* Allow it so as to stay robust to broken firmware.
*/
case PSCI_0_2_FN_SYSTEM_OFF:
case PSCI_0_2_FN_SYSTEM_RESET:
psci_forward_noreturn(host_ctxt);
unreachable();
return psci_forward(host_ctxt);
case PSCI_0_2_FN64_CPU_SUSPEND:
return psci_cpu_suspend(func_id, host_ctxt);
case PSCI_0_2_FN64_CPU_ON:

10
arch/arm64/kvm/pmu-emul.c
View File

@ -788,7 +788,7 @@ u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
{
unsigned long *bmap = vcpu->kvm->arch.pmu_filter;
u64 val, mask = 0;
int base, i;
int base, i, nr_events;
if (!pmceid1) {
val = read_sysreg(pmceid0_el0);
@ -801,13 +801,17 @@ u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
if (!bmap)
return val;
nr_events = kvm_pmu_event_mask(vcpu->kvm) + 1;
for (i = 0; i < 32; i += 8) {
u64 byte;
byte = bitmap_get_value8(bmap, base + i);
mask |= byte << i;
byte = bitmap_get_value8(bmap, 0x4000 + base + i);
mask |= byte << (32 + i);
if (nr_events >= (0x4000 + base + 32)) {
byte = bitmap_get_value8(bmap, 0x4000 + base + i);
mask |= byte << (32 + i);
}
}
return val & mask;

93
arch/arm64/kvm/sys_regs.c
View File

@ -43,6 +43,10 @@
* 64bit interface.
*/
#define reg_to_encoding(x) \
sys_reg((u32)(x)->Op0, (u32)(x)->Op1, \
(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2)
static bool read_from_write_only(struct kvm_vcpu *vcpu,
struct sys_reg_params *params,
const struct sys_reg_desc *r)
@ -273,8 +277,7 @@ static bool trap_loregion(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *r)
{
u64 val = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
u32 sr = sys_reg((u32)r->Op0, (u32)r->Op1,
(u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
u32 sr = reg_to_encoding(r);
if (!(val & (0xfUL << ID_AA64MMFR1_LOR_SHIFT))) {
kvm_inject_undefined(vcpu);
@ -590,6 +593,15 @@ static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
vcpu_write_sys_reg(vcpu, (1ULL << 31) | mpidr, MPIDR_EL1);
}
static unsigned int pmu_visibility(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *r)
{
if (kvm_vcpu_has_pmu(vcpu))
return 0;
return REG_HIDDEN;
}
static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
u64 pmcr, val;
@ -613,9 +625,8 @@ static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
static bool check_pmu_access_disabled(struct kvm_vcpu *vcpu, u64 flags)
{
u64 reg = __vcpu_sys_reg(vcpu, PMUSERENR_EL0);
bool enabled = kvm_vcpu_has_pmu(vcpu);
bool enabled = (reg & flags) || vcpu_mode_priv(vcpu);
enabled &= (reg & flags) || vcpu_mode_priv(vcpu);
if (!enabled)
kvm_inject_undefined(vcpu);
@ -900,11 +911,6 @@ static bool access_pmswinc(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (!kvm_vcpu_has_pmu(vcpu)) {
kvm_inject_undefined(vcpu);
return false;
}
if (p->is_write) {
if (!vcpu_mode_priv(vcpu)) {
kvm_inject_undefined(vcpu);
@ -921,10 +927,6 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
return true;
}
#define reg_to_encoding(x) \
sys_reg((u32)(x)->Op0, (u32)(x)->Op1, \
(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2)
/* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
#define DBG_BCR_BVR_WCR_WVR_EL1(n) \
{ SYS_DESC(SYS_DBGBVRn_EL1(n)), \
@ -936,15 +938,18 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
{ SYS_DESC(SYS_DBGWCRn_EL1(n)), \
trap_wcr, reset_wcr, 0, 0, get_wcr, set_wcr }
#define PMU_SYS_REG(r) \
SYS_DESC(r), .reset = reset_unknown, .visibility = pmu_visibility
/* Macro to expand the PMEVCNTRn_EL0 register */
#define PMU_PMEVCNTR_EL0(n) \
{ SYS_DESC(SYS_PMEVCNTRn_EL0(n)), \
access_pmu_evcntr, reset_unknown, (PMEVCNTR0_EL0 + n), }
{ PMU_SYS_REG(SYS_PMEVCNTRn_EL0(n)), \
.access = access_pmu_evcntr, .reg = (PMEVCNTR0_EL0 + n), }
/* Macro to expand the PMEVTYPERn_EL0 register */
#define PMU_PMEVTYPER_EL0(n) \
{ SYS_DESC(SYS_PMEVTYPERn_EL0(n)), \
access_pmu_evtyper, reset_unknown, (PMEVTYPER0_EL0 + n), }
{ PMU_SYS_REG(SYS_PMEVTYPERn_EL0(n)), \
.access = access_pmu_evtyper, .reg = (PMEVTYPER0_EL0 + n), }
static bool undef_access(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
@ -1020,8 +1025,7 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
static u64 read_id_reg(const struct kvm_vcpu *vcpu,
struct sys_reg_desc const *r, bool raz)
{
u32 id = sys_reg((u32)r->Op0, (u32)r->Op1,
(u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
u32 id = reg_to_encoding(r);
u64 val = raz ? 0 : read_sanitised_ftr_reg(id);
if (id == SYS_ID_AA64PFR0_EL1) {
@ -1062,8 +1066,7 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
static unsigned int id_visibility(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *r)
{
u32 id = sys_reg((u32)r->Op0, (u32)r->Op1,
(u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
u32 id = reg_to_encoding(r);
switch (id) {
case SYS_ID_AA64ZFR0_EL1:
@ -1486,8 +1489,10 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_FAR_EL1), access_vm_reg, reset_unknown, FAR_EL1 },
{ SYS_DESC(SYS_PAR_EL1), NULL, reset_unknown, PAR_EL1 },
{ SYS_DESC(SYS_PMINTENSET_EL1), access_pminten, reset_unknown, PMINTENSET_EL1 },
{ SYS_DESC(SYS_PMINTENCLR_EL1), access_pminten, reset_unknown, PMINTENSET_EL1 },
{ PMU_SYS_REG(SYS_PMINTENSET_EL1),
.access = access_pminten, .reg = PMINTENSET_EL1 },
{ PMU_SYS_REG(SYS_PMINTENCLR_EL1),
.access = access_pminten, .reg = PMINTENSET_EL1 },
{ SYS_DESC(SYS_MAIR_EL1), access_vm_reg, reset_unknown, MAIR_EL1 },
{ SYS_DESC(SYS_AMAIR_EL1), access_vm_reg, reset_amair_el1, AMAIR_EL1 },
@ -1526,23 +1531,36 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 },
{ SYS_DESC(SYS_CTR_EL0), access_ctr },
{ SYS_DESC(SYS_PMCR_EL0), access_pmcr, reset_pmcr, PMCR_EL0 },
{ SYS_DESC(SYS_PMCNTENSET_EL0), access_pmcnten, reset_unknown, PMCNTENSET_EL0 },
{ SYS_DESC(SYS_PMCNTENCLR_EL0), access_pmcnten, reset_unknown, PMCNTENSET_EL0 },
{ SYS_DESC(SYS_PMOVSCLR_EL0), access_pmovs, reset_unknown, PMOVSSET_EL0 },
{ SYS_DESC(SYS_PMSWINC_EL0), access_pmswinc, reset_unknown, PMSWINC_EL0 },
{ SYS_DESC(SYS_PMSELR_EL0), access_pmselr, reset_unknown, PMSELR_EL0 },
{ SYS_DESC(SYS_PMCEID0_EL0), access_pmceid },
{ SYS_DESC(SYS_PMCEID1_EL0), access_pmceid },
{ SYS_DESC(SYS_PMCCNTR_EL0), access_pmu_evcntr, reset_unknown, PMCCNTR_EL0 },
{ SYS_DESC(SYS_PMXEVTYPER_EL0), access_pmu_evtyper },
{ SYS_DESC(SYS_PMXEVCNTR_EL0), access_pmu_evcntr },
{ PMU_SYS_REG(SYS_PMCR_EL0), .access = access_pmcr,
.reset = reset_pmcr, .reg = PMCR_EL0 },
{ PMU_SYS_REG(SYS_PMCNTENSET_EL0),
.access = access_pmcnten, .reg = PMCNTENSET_EL0 },
{ PMU_SYS_REG(SYS_PMCNTENCLR_EL0),
.access = access_pmcnten, .reg = PMCNTENSET_EL0 },
{ PMU_SYS_REG(SYS_PMOVSCLR_EL0),
.access = access_pmovs, .reg = PMOVSSET_EL0 },
{ PMU_SYS_REG(SYS_PMSWINC_EL0),
.access = access_pmswinc, .reg = PMSWINC_EL0 },
{ PMU_SYS_REG(SYS_PMSELR_EL0),
.access = access_pmselr, .reg = PMSELR_EL0 },
{ PMU_SYS_REG(SYS_PMCEID0_EL0),
.access = access_pmceid, .reset = NULL },
{ PMU_SYS_REG(SYS_PMCEID1_EL0),
.access = access_pmceid, .reset = NULL },
{ PMU_SYS_REG(SYS_PMCCNTR_EL0),
.access = access_pmu_evcntr, .reg = PMCCNTR_EL0 },
{ PMU_SYS_REG(SYS_PMXEVTYPER_EL0),
.access = access_pmu_evtyper, .reset = NULL },
{ PMU_SYS_REG(SYS_PMXEVCNTR_EL0),
.access = access_pmu_evcntr, .reset = NULL },
/*
* PMUSERENR_EL0 resets as unknown in 64bit mode while it resets as zero
* in 32bit mode. Here we choose to reset it as zero for consistency.
*/
{ SYS_DESC(SYS_PMUSERENR_EL0), access_pmuserenr, reset_val, PMUSERENR_EL0, 0 },
{ SYS_DESC(SYS_PMOVSSET_EL0), access_pmovs, reset_unknown, PMOVSSET_EL0 },
{ PMU_SYS_REG(SYS_PMUSERENR_EL0), .access = access_pmuserenr,
.reset = reset_val, .reg = PMUSERENR_EL0, .val = 0 },
{ PMU_SYS_REG(SYS_PMOVSSET_EL0),
.access = access_pmovs, .reg = PMOVSSET_EL0 },
{ SYS_DESC(SYS_TPIDR_EL0), NULL, reset_unknown, TPIDR_EL0 },
{ SYS_DESC(SYS_TPIDRRO_EL0), NULL, reset_unknown, TPIDRRO_EL0 },
@ -1694,7 +1712,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
* PMCCFILTR_EL0 resets as unknown in 64bit mode while it resets as zero
* in 32bit mode. Here we choose to reset it as zero for consistency.
*/
{ SYS_DESC(SYS_PMCCFILTR_EL0), access_pmu_evtyper, reset_val, PMCCFILTR_EL0, 0 },
{ PMU_SYS_REG(SYS_PMCCFILTR_EL0), .access = access_pmu_evtyper,
.reset = reset_val, .reg = PMCCFILTR_EL0, .val = 0 },
{ SYS_DESC(SYS_DACR32_EL2), NULL, reset_unknown, DACR32_EL2 },
{ SYS_DESC(SYS_IFSR32_EL2), NULL, reset_unknown, IFSR32_EL2 },

1
virt/kvm/kvm_main.c
View File

@ -1292,6 +1292,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
return -EINVAL;
/* We can read the guest memory with __xxx_user() later on. */
if ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
(mem->userspace_addr != untagged_addr(mem->userspace_addr)) ||
!access_ok((void __user *)(unsigned long)mem->userspace_addr,
mem->memory_size))
return -EINVAL;